Subcutaneous Infusion Device and Method including Tapered Cannula

ABSTRACT

A site for a subcutaneous infusion device includes a base positionable relative to skin of a patient, and a cannula extending from the base and configured to be introduced into a subcutaneous layer of skin of the patient at a generally ninety-degree angle with respect to the skin using a needle. The cannula includes first and second ends and defines a bore extending from the first end to the second end, the first end being coupled to the base. The cannula includes a tapered wall portion formed between the first and second ends and extending from adjacent to the base towards the second end of the cannula, the tapered wall portion being tapered from a greater wall thickness to a lesser wall thickness as the tapered wall portion extends from the base towards the second end.

RELATED APPLICATIONS

Embodiments disclosed herein relate to U.S. patent application Ser. No.10/705,725 filed on Nov. 10, 2003, U.S. patent application Ser. No.10/705,736 filed on Nov. 10, 2003, U.S. patent application Ser. No.10/705,719 filed on Nov. 10, 2003, U.S. patent application Ser. No.10/869,181 filed on Jun. 16, 2004, and U.S. patent application Ser. No.10/918,212 filed on Aug. 13, 2004, the entireties of which are herebyincorporated by reference.

TECHNICAL FIELD

Embodiments disclosed herein relate to an infusion device for deliveryof a substance to a patient.

BACKGROUND

Infusion devices are used to deliver substances such as medications intothe subcutaneous layer of skin of a patient. Typically, an infusiondevice includes a cannula that is introduced into the skin, as well as atube extending from the infusion device to, for example, an infusionpump to deliver the substance.

In current designs, it is typically necessary to introduce a cannula ofthe infusion device into the skin while maintaining the device at agiven orientation so that the tubing extends in a direction towards theinfusion pump. Further, once the infusion device is placed on the skin,there is typically no way to reorient the device and associated tubing,or to remove the tubing from the body without removing the cannula fromthe skin of the patient. In addition, the profile of infusion devicescan be undesirably high, making placement and concealment of theinfusion device difficult and uncomfortable to wear. Also, introductionof the infusion device into the skin can be complicated and require twohands to accomplish.

It is therefore desirable to provide new designs for infusion devicesused to deliver a substance into the skin of a patient.

SUMMARY

Embodiments disclosed herein relate to infusion devices for delivery ofa substance to a patient.

In one embodiment, an infusion device can include a site and a set. Thesite can include a cannula that is introduced into a subcutaneous layerof skin of the patient. The set can be coupled to the site by, forexample, placing the set over the site and moving the set from anunlocked to a locked position. A substance can then be delivered throughthe set to the site and from the site into the patient through thecannula.

In another embodiment, a site for a subcutaneous infusion deviceincludes a base positionable relative to skin of a patient, and acannula extending from the base and configured to be introduced into asubcutaneous layer of skin of the patient at a generally ninety-degreeangle with respect to the skin using a needle. The cannula includesfirst and second ends and defines a bore extending from the first end tothe second end, the first end being coupled to the base. The cannulaincludes a tapered wall portion formed between the first and second endsand extending from adjacent the base towards the second end of thecannula, the tapered wall portion being tapered from a greater wallthickness to a lesser wall thickness as the tapered wall portion extendsfrom the base towards the second end.

The above summary of example embodiments is not intended to describeeach disclosed embodiment or every implementation. Figures in thedetailed description that follow more particularly exemplify embodimentsof the invention. While certain embodiments will be illustrated anddescribed, the invention is not limited to use in such embodiments.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of an example embodiment of a site madein accordance with the present invention.

FIG. 2 is a bottom perspective view of the site of FIG. 1.

FIG. 3 is a side view of the site of FIG. 1.

FIG. 4 is a top view of the site of FIG. 1.

FIG. 5 is a bottom view of the site of FIG. 1.

FIG. 6 is a cross-sectional view taken along line 6-6 of the site ofFIG. 3.

FIG. 6A is a cross-sectional view taken along line 6-6 of the site ofFIG. 3 including a needle used to insert the site.

FIG. 7 is an exploded view of the site of FIG. 1.

FIG. 8 is a top perspective view of a base of the site of FIG. 1.

FIG. 9 is a bottom perspective view of the base of FIG. 8.

FIG. 10 is a side view of the base of FIG. 8.

FIG. 11 is a top view of the base of FIG. 8.

FIG. 12 is a side view of a cannula of the site of FIG. 1.

FIG. 13 is an end view of the cannula of FIG. 13.

FIG. 14 is cross-sectional view taken along line 14-14 of the cannula ofFIG. 12.

FIG. 15 is a side view of a diaphragm of the site of FIG. 1.

FIG. 16 is an end view of the diaphragm of FIG. 15.

FIG. 17 is a cross-sectional view taken along line 17-17 of thediaphragm of FIG. 16.

FIG. 18 is a top view of an adhesive portion of the site of FIG. 1.

FIG. 19 is a cross-sectional view taken along line 19-19 of the adhesiveportion of FIG. 18.

FIG. 20 is an exploded view of the adhesive portion of FIG. 18.

FIG. 21 is a top perspective view of an example embodiment of a set inan unlocked position made in accordance with the present invention.

FIG. 22 is a top perspective view of a first member of the set of FIG.21.

FIG. 23 is a top view of the first member of FIG. 22.

FIG. 24 is a side view of the first member of FIG. 22.

FIG. 25 is an end view of the first member of FIG. 22.

FIG. 26 is another end view of the first member of FIG. 22.

FIG. 27 is a top perspective view of a second member of the set of FIG.21.

FIG. 28 is a top view of the second member of FIG. 27.

FIG. 29 is a side view of the second member of FIG. 27.

FIG. 30 is an end view of the second member of FIG. 27.

FIG. 31 is another end view of the second member of FIG. 27.

FIG. 32 is a top view of the set of FIG. 21 in an unlocked position.

FIG. 33 is a side view of the set of FIG. 32.

FIG. 34 is an end view of the set of FIG. 32.

FIG. 35 is a cross-sectional view taken along line 35-35 of the set ofFIG. 32 with portions of the set removed for clarity.

FIG. 36 is a top perspective view of the set of FIG. 21 in a lockedposition.

FIG. 37 is a top view of the set of FIG. 36.

FIG. 38 is a side view of the set of FIG. 36.

FIG. 39 is an end view of the set of FIG. 36.

FIG. 40 is a bottom perspective view of the set of FIG. 36.

FIG. 41 is a bottom view of the set of FIG. 36.

FIG. 42 is a cross-sectional view taken along line 42-42 of the set ofFIG. 38 with portions of the set removed for clarity.

FIG. 43 is a perspective view of the site of FIG. 1 and the set of FIG.21 coupled to one another.

FIG. 44 is a top view of the site and set of FIG. 43.

FIG. 45 is a bottom view of the site and set of FIG. 43.

FIG. 46 is a side view of the site and set of FIG. 43.

FIG. 47 is an end view of the site and set of FIG. 43.

FIG. 48 is another end view of the site and set of FIG. 43.

FIG. 49 is an exploded perspective view of the site and set of FIG. 43.

FIG. 50 is a cross-sectional view taken along line 50-50 of the site andset of FIG. 44.

FIG. 51 is an exploded perspective view of another example embodiment ofan infusion device including a site and set made in accordance with thepresent invention.

FIG. 52 is a perspective view of the infusion device of FIG. 51 in alocked position.

FIG. 53 is a cross-sectional view of the site of FIG. 51.

FIG. 54 is a side view of another embodiment of a cannula of a site.

FIG. 55 is a cross-sectional view taken along line 55-55 of the cannulaof FIG. 54.

FIG. 56 is an end view of the cannula of FIG. 54.

DETAILED DESCRIPTION

Embodiments of the present invention relate to infusion devices fordelivering a substance into the subcutaneous layer of skin of a patient.

Generally, the example infusion devices disclosed herein include a sitewith a cannula that is introduced into the subcutaneous layer of theskin of a patient to deliver a substance, as well as a set that can becoupled to the site to deliver the substance to the site.

Referring now to FIGS. 1-7, an example embodiment of a site 100 of aninfusion device is depicted in accordance with the present invention.Generally, the site 100 can be used in conjunction with a set (describedbelow) to deliver a substance into a patient.

The site 100 includes a base 110, a cannula 130, a diaphragm 150, and anadhesive portion 170. The cannula 130 of the site 100 can be introducedinto the subcutaneous layer of skin of the patient using a needle (e.g.,needle 139), as shown in FIG. 6A. The adhesive portion 170 allows thebase 110 of the site 100 to be coupled to the skin of the patient. Thediaphragm 150 is in fluid communication with the cannula to deliver asubstance from the diaphragm 150, through the cannula 130, and into theskin of the patient, as described further below.

Referring now to FIGS. 8-11, the base 110 is shown. The base includes astand 114 with a top side 111 and a bottom side 112, and forms a centralaperture 113 located at a central axis C of the base 110. The stand 114further forms eight positional slots 115 on the top side 111 positionedradially with respect to the central axis C of the site 110 at regularintervals.

The base 110 also includes a member 120 coupled to the stand 114, themember 120 being positioned about the central aperture 113 of the stand114 and including eight surfaces 124. In one preferred embodiment, themember 120 is non-cylindrical in shape. For example, in the embodimentshown the member 120 is octagonal in shape, although other shapes canalso be used, as noted below. The non-cylindrical shape of member 120defines different mounting orientations for a set that can be coupled tothe site 100.

An interior wall of the member 120 forms a cylindrical cavity 121, andan exterior periphery of the member 120 forms a groove 122 extendingabout the exterior periphery. In addition, the member 120 forms eightapertures 123 extending from the interior cavity 121 to the groove 122in the exterior of the member 120.

Referring now to FIGS. 12-14, the cannula 130 is illustrated. Thecannula 130 includes first and second ends 132 and 134. The first end132 of the cannula 130 includes a flange portion 136 having a taperedbottom side 140, as well as a tapered portion 138 described furtherbelow. The cannula 130 also includes a central bore 142 extending fromthe first end 132 to the second end 134 to allow a substance to beintroduced at the first end 132 and delivered out of the second end 134.

The cannula 130 is positioned within the cavity 121 of the base 110 sothat the bottom taper 140 of the cannula 130 engages tapered bottomsurfaces 125 of the cavity 121 of the member 120, and the second end 134of the cannula 130 extends through the central aperture 113 of the stand114 at an approximate right angle to the bottom side 112 of the stand114. See FIG. 6. Preferably, the bottom taper 140 of the cannula 130 ispositioned adjacent to the stand 114 of the base 110.

Preferably the cannula 130 is made of fluorinated ethylene propylene(FEP). Other materials can also be used, such as polytetrafluoroethylene(PTFE), or other suitable plastics.

Referring now to FIGS. 15-17, the diaphragm 150 is shown. Generally, thediaphragm 150 functions as a septum or seal that allows a needle toaccess an internal portion of the septum to deliver a substanceprovided, for example, from an infusion device or other similar deviceto the cannula 130.

Preferably, the diaphragm 150 is generally cylindrical in shape andincludes an open bottom end 152 and a closed top end 154. The diaphragm150 also includes a tapered portion 156 adjacent the bottom end 152, anda central reservoir 158.

As shown, for example, in FIGS. 6 and 17, the diaphragm 150 ispositioned in the cavity 121 of the member 120 and preferably includesan outer periphery 160 that is sized to frictionally engage the interiorcavity wall of the member 120 to retain the diaphragm 150 in the cavity121. In addition, the tapered portion 156 of the diaphragm 150 isconfigured to engage the tapered bottom surfaces 125 of the base 110.The bottom end 152 engages the first end 132 of the cannula 130 toprovide fluid communication between the reservoir 158 and the bore 142of the cannula 130.

More specifically, surfaces 157 adjacent to the bottom end 152 ofdiaphragm 150 preferably are compressed against the first end 132 of thecannula 130 to provide a seal with respect to the cannula 130 so asubstance can be delivered from the diaphragm 150, through the cannula130, and into the patient. In alternative embodiments, additionalstructure such as, for example, an O-ring can also be provided betweenthe diaphragm 150 and cannula 130 to provide additional sealing.

In a preferred embodiment, the diaphragm 150 is made of a siliconeelastomer. Other materials can also be used, such as ethylene propyleneor other suitable elastomeric materials.

As previously noted, preferably the diaphragm 150 is retained in thecavity 121 of the member 120 of the base 110 through the frictionalengagement of the outer periphery 160 of the diaphragm 150 with thewalls of the cavity 121. In alternative embodiments, a retaining membercan be fitted over the open top of the member 120 to further retain thediaphragm 150 in position in the cavity 121. In other embodiments, thediaphragm 150 can be retained in the cavity 121 through compression byother features of the member 120, or the diaphragm 150 can have featuresthat mate with features of the member 120. For example, in onealternative embodiment, the diaphragm 150 can be formed with barbs onthe outer periphery 160 positioned and sized to be received withinapertures 123 formed in the member 120 to retain the diaphragm 150 inthe cavity 120. Other configurations are also possible.

Referring now to FIGS. 18-20, the adhesive portion 170 is shown. Theadhesive portion includes liners 172 and 176 sandwiching a layer 174.Preferably, the layer 174 includes an aperture 178 through which thecannula 130 of the site 100 extends, as described below.

The liner 172 can be removed and the layer 174 coupled to the bottomside 112 of the stand 114 of the base 110 using an adhesive. Examples ofsuch adhesives include, without limitation, acrylic adhesive, syntheticrubber-based adhesive, acrylate adhesive, and silicone-based adhesive.In addition, the liner 176 can be removed and an adhesive be provided ona bottom side of the layer 174 to couple the adhesive portion 170 andassociated site 100 to another adhesive portion or the skin of thepatient, for example.

In a preferred embodiment, layer 174 of the adhesive portion 170includes films with adhesives thereon, such as and without limitation,3M™ 1577 tape. Other materials can also be used.

In an alternative embodiment, layer 174 can be provided with a tab (notshown, but preferably similar to tabs shown on liners 172 and 176) orother similar structure that can assist the patient in removing thelayer 174 and associated site 100 from the skin when desired. Forexample, the tab can extend from an outer periphery of the layer 174 andallow the patient to grasp the tab and thereby peel the layer 174 fromthe skin to remove the site 100.

In other alternative embodiments, the adhesive portion 170 can beremoved completely, and adhesion between the site 100 and skin of thepatient can be provided using film and/or adhesive carried on otherstructures, such as a device used to insert the site 100 into the body,as described further below.

In other alternative embodiments, the layer 174 can include a foambacking or similar additional material can be added adjacent to thelayer 174 to provide supplemental cushioning as the site 100 is insertedinto the skin of the patient. Further, in other embodiments the layer174 can be replaced or supplemented by one or more other layer of othermaterial such as, for example, a Tegaderm™ film manufactured by 3M™ oran IV3000™ film manufactured by Smith & Nephew.

Referring now to FIG. 21, an example embodiment of a set 200 of aninfusion device is depicted in accordance with the present invention. Asnoted generally above and described further below, the set 200 can beused in conjunction with a site (e.g., site 100) to deliver a substanceinto a patient.

The set 200 generally includes a first member 210 and a second member250. The first member 210 is slideable relative to the second member 250into an unlocked position (see, e.g., FIGS. 21 and 32-35) and a lockedposition (see, e.g., FIGS. 36-42), described further below.

Referring now to FIGS. 22-26, the first member 210 is shown. The firstmember 210 includes a main body 212, and a port 213 extending throughthe body 212 and in fluid communication with a hollow needle 214. Theport 213 is preferably coupled to a tube (e.g., tube 305 shown in FIG.21) that can be attached, for example, to an infusion pump for thedelivery of a substance to the set 200.

The first member 210 also includes outer arms 220 and 222 with barbs 223formed on the ends and projections 230 extending below the arms 220. Inaddition, the first member 210 includes inner arms 226 and 228 withbarbs 229. As described further below, the outer arms 220 and 222 can bedisplaced towards one another when force is applied to surfaces 221.

Referring now to FIGS. 27-31, the second member 250 is shown. The secondmember 250 includes a main body 260, and a central octagonal aperture270. The second member 250 also includes opening 262 extending to thecentral aperture 270, as well as openings 264 positioned on oppositesides of the main body 260. The second member 250 also includesprojections 266 formed on a bottom surface 274 of a base 261, as well asslots 268 preferably extending through the base 261 of the main body260.

Referring now to FIGS. 21 and 32-35, the first and second members 210and 250 of the set 200 are shown in the unlocked position. The firstmember 210 is slidingly received by the second member 250 such thatinner arms 226 and 228 are accepted into opening 262 of the secondmember 250. Projections 230 on outer arms 220 and 222 of the firstmember 210 are received in slots 268 of the second member 250.

As illustrated by FIG. 35, in the unlocked position barbs 229 of innerarms 226 and 228 of the first member 210 extend through openings 264 andengage shoulders 271 of the second member 250 such that the first andsecond members 210 and 250 cannot be further separated.

Referring now to FIGS. 36-42, the first and second members 210 and 250of the set 200 are shown in the locked position. To move the set 200from the unlocked to the locked position, the first and second members210 and 250 are slid towards one another, and outer arms 220 and 222 ofthe first member 210 are accepted into the openings 264 of the secondmember 250. Likewise, projections 230 on outer arms 220 and 222 slidealong slots 268 of the second member 250. Further, surfaces 234 of theinner arms 226 and 228 partially extend into aperture 270, as describedfurther below.

As illustrated by FIG. 42, in the locked position outer arms 220 and 222extend through openings 264 and engage lips 272 of the second member250. In addition, inner arms 226 and 228 of the first member 210 extendfurther into the second member 250. In this locked position, theengagement of the barbs 223 with the lips 272 resist allowing the firstmember 210 from being slid relative to the second member 250.

In order to slide the first member 210 away from the second member 250from the locked position back to the unlocked position, the outer arms220 and 222 are deflected inwardly toward one another by applyingpressure on surfaces 221 until the barbs 223 clear the lips 272, therebyallowing the first member 210 to be slid with respect to the secondmember 250 back into the unlocked position as shown in FIGS. 21 and32-35.

Preferably, slots 268 formed in the second member 250 include a cammedsurface 269 so that projections 230 extending below the arms 220 of thefirst member 210 are biased towards a first end 267 of the slots 268 tothereby bias the first member 210 into the unlocked position. See FIGS.40 and 41. In alternative embodiments, other features can be provided tobias the first member 210 into the unlocked position. For example,detents can be provided to engage barbs 229 as inner arms 226 and 228 ofthe first member 210 are moved towards the locked position to bias thefirst member 210 into the unlocked position. It can be preferable tobias the set 200 into the unlocked position so that the set 200 can beeasily positioned onto and removed from the site 100, as describedfurther below.

Referring now to FIGS. 43-50, as previously noted the site 100 and set200 can be used together to form an infusion device 300 for delivery ofa substance to a patient.

One method of use of the infusion device 300 is as follows. Initially,the site 100 is positioned on the skin of a patient with the cannula 130being introduced into the subcutaneous layer of the skin. This can beaccomplished, for example, using a needle (e.g., needle 130 shown inFIG. 6A) that is extended through the exposed closed end 154 of thediaphragm 150 and through the bore 142 of the cannula 130 and beyond thesecond end 134. The tapered portion 138 of the flange portion 136 of thecannula 130 can assist in directing the needle through into the bore 142of the cannula 130. In this position, the needle can be used tointroduce the cannula 130 of the site 100 into the skin of the patient.Further, once the cannula 130 is in position, the needle can be removed,leaving the cannula 130 in place in the subcutaneous layer of the skin.As the needle is removed, the closed end 154 of the diaphragm 150reseals itself to retain the fluid-tight reservoir 158.

In a preferred embodiment, the site 100 of the infusion device 300 isplaced in position on the skin of a patient using a device made inaccordance with that disclosed in U.S. patent application Ser. No.10/705,725, Attorney Docket No. 14485.154US01, entitled “Device andMethod for Insertion of a Cannula of an Infusion Device,” filed on Nov.10, 2003. Other methods and devices for inserting the infusion deviceinto the skin of the patient can also be used. For example, in analternative embodiment the site 100 can be inserted manually using aneedle. See needle 139 shown in FIG. 6A.

Once the site 100 has been positioned on the skin of a patient (with thecannula 130 having been introduced into the subcutaneous layer), the set200 can be coupled to the site 100 as follows. With the set 200 in theunlocked position, the set 200 can be placed over the member 120 so thatthe central octagonal aperture 270 of the set 200 accepts the member 120into the aperture 270. The set 200 is lowered onto the site 100 untilthe bottom surface 274 of the set 200 contacts the stand 114 of the site100 and projections 266 of the second member 250 are accepted into thepositional slots 115 of the stand 114 of the base 110.

In this position on the site 100, the first member 210 of the set 200can be slid from the unlocked to the locked position. As the firstmember 210 is slid to the locked position, surfaces 234 of the innerarms 226 and 228 (see FIGS. 23, 36, and 37) are accepted by the groove112 of the member 120 of the base 100, which locks the set 200 to thesite 100 so that the set 200 resists any upward force tending to removethe set 200 from the site 100 when the set 200 is in the lockedposition. In addition, the shape of the member 120 of the site 100 andthe central aperture 270 of the set 200, as well as projections 266received in slots 115, orient the set 200 with respect to the site 100and function to resist rotation of the set 200 with respect to the site100 when the set 200 is in the locked position.

In addition, as the first member 210 of the set 200 is moved from theunlocked to the locked position, the needle 214 is advanced through oneof the eight apertures 123 formed in the member 120 and into thediaphragm 150 in the cavity 121. In the fully locked position as shownin FIG. 50, an end 215 of the needle 214 is positioned within thereservoir 158 of the diaphragm 150. In this position, the port 213 isfluidly coupled to the cavity 121 of the diaphragm 150 through thehollow needle 214, and the cavity 121 is in turn fluidly coupled to theskin of the patient through the bore 142 in the cannula 130. In thismanner, a substance can be delivered to the port 213 of the set 200 (by,for example, a tube not shown in the figures), through the needle 214,into the reservoir 158, and into the subcutaneous layer of the skin ofthe patient by the cannula 130.

If the set 200 is not oriented as desired with respect to the site 100,or if the patient desires to remove the set 200 from the site 100, theset 200 can be moved from the locked to the unlocked position by forcingthe outer arms 220 and 222 together and sliding the first member 210away from the second member 250 to the unlocked position. This actionremoves the surfaces 234 from the groove 122, as well as the needle 214from the reservoir 158. The diaphragm 150 reseals upon removal of theneedle 214. The set 200 can then be removed from the site 100, leavingthe site 100 in place on the skin of the patient. The set 200 can bereplaced at another orientation or at a later time.

In the illustrated embodiment of the infusion device 300, the set 200can be oriented in eight different positions with respect to the site100. In alternative embodiments, the site 100 and set 200 can beconfigured to include fewer or more positions as desired. For example,in an alternative embodiment the member 120 of the site 100 and theaperture 270 of the set 200 can be formed in the shape of a square iffour orientational positions are desired.

Referring now to FIGS. 51-53, another example infusion device 400 isshown in accordance with the present invention. The device 400 issimilar to the example device 300 described above, except for thedetails noted below.

The infusion device 400 includes a site 405 with a central portion 407.The central portion 407 includes a pierceable outer shell 430 made of amaterial such as a plastic, and a softer inner diaphragm 432 surroundingthe outer shell 430. An inner reservoir 434 of the central portion 407is fluidly coupled to a cannula 440. See FIG. 53.

The infusion device 400 also includes a set with a first member 410 anda second member 420. The first member 410 includes a needle 411, andfirst and second arms 412 and 414 with barbs 415 on ends. The secondmember 420 includes shoulders 422 and 424. The first and second members410 and 420 each form openings 461 and 462, respectively, that are sizedto each receive a portion of the central portion 407 of the site 405.

The infusion device 400 can be used as follows. First, the site 405 ispositioned on the skin of a patient so that the cannula 440 isintroduced into the subcutaneous layer. Next, the first member 410 andsecond member 420 of the site are placed onto the site 405 so thatopenings 461 and 462 are positioned about the central portion 407, andthe first and second members 410 and 420 are slid towards one anotherfrom the unlocked to the locked position. As the set is moved to thelocked position, the needle 411 is introduced into the central portion407 of the site 405, moving through the outer shell 430 and into thereservoir 434 to become fluidly coupled to the cannula 440. In addition,the arms 412 and 414 are accepted into the second member 420 until barbs415 engage the shoulders 422 and 424 in the locked position, as shown inFIG. 52.

To move the set from the locked position back into the unlockedposition, the barbs 415 are pressed inwardly toward one another untilthey clear the shoulders 422 and 424, and then the first member 410 isslid away from the second member 420, thereby removing the needle 411from the central portion 407 of the site 405.

As preferably there is no specific structure provided with infusiondevice 400 for rotationally orienting the set with the site 405, the setcan be oriented at an infinite number of rotational positions withrespect to the site 405 as desired. Further, since the central portion407 of the site and the openings 461 and 462 of the set are preferablycircular in shape, the first and second members 410 and 420 of the sitecan be rotated relative to the site 405 without requiring that the setbe completely removed from the site 405.

Referring now to FIGS. 54-56, another example embodiment of a cannula530 is illustrated. The cannula 530 is similar to cannula 130 describedabove. See FIGS. 12-14. The cannula 530 includes first and second ends532 and 534. The first end 532 includes a flange portion 536 having atapered bottom side 540, as well as a tapered portion 538. The cannula530 also includes a central bore 542 extending from the first end 532 tothe second end 534 to allow a substance to be introduced at the firstend 532 and delivered out of the second end 534.

Unlike the cannula 130 described above, the cannula 530 includes atapered wall portion 550 extending from the tapered bottom side 540. Thetapered wall portion 550 includes a first wall portion 552 positionedadjacent to the tapered bottom side 540 and a second wall portion 554adjacent to a remaining distal portion 560 of the cannula 530. Inexample embodiments, the first wall portion 552 is greater in radialthickness than the second wall portion 554, so that the tapered wallportion 550 tapers as the tapered wall portion 550 extends from thetapered bottom side 540 to the distal portion 560 of the cannula 530.

In example embodiments, a length L1 of the cannula 530 is approximately9 millimeters. In another embodiment, the length L1 is approximately 6millimeters. In other alternatives, the length L1 is approximately lessthan 9 millimeters, between 6 and 9 millimeters, less than 6millimeters, 5 millimeters, 4 millimeters, 3 millimeters, less than 3millimeters, 2 millimeters, or 1 millimeter.

In example embodiments, a difference in thickness L2 between the firstwall portion 552 and the second wall portion 554 is approximately 1millimeter. In alternative embodiments, the dimension L2 isapproximately 1.5 millimeters, less than 1.5 millimeters, 0.8millimeters, 0.5 millimeters, or less than 0.5 millimeters.

In example embodiments, an axial length L3 of the tapered wall portion550 is approximately 1.5 millimeters. In alternative embodiments, L3 canbe 3.0 millimeters, 2 millimeters, 1 millimeter, or less than 1millimeter.

Other dimensions for dimensions L1, L2, and L3 of the cannula 530 can beused.

In example embodiments, the cannula 530 is made of fluorinated ethylenepropylene (FEP). Other materials can also be used, such aspolytetrafluoroethylene (PTFE), or other suitable plastics.

One or more advantages can be associated with forming the tapered wallportion 550 as part of the cannula 530. For example, the added thicknessof the tapered wall portion 550 can function to minimize kinking orbuckling of the cannula 530 during insertion into the subcutaneous layerof skin. In addition, the tapered wall portion 550 can provide relief ofthe strain created between the tapered bottom side 540 and the remainingportion of the cannula 530 during use of the cannula 530 within thesubcutaneous layer of skin.

In some embodiments, the tapering of the tapered wall portion 550 canalso function as a dilating plug within the skin to minimize drugdelivered through the cannula 530 from migrating to the surface of theskin, where it may be less effective. For example, the larger radialsize of the first wall portion 552 of the portion 550 can stretch theskin layers as it enters the skin, thereby creating a seal between thetapered wall portion 550 and the skin.

In yet other embodiments, the sealing properties of the tapered wallportion 550 can be enhanced or replaced by applying an adhesive, hydrogel, or other similar material to the outer, upper surface of cannula230 or 530 prior to insertion into the skin. For example, in oneembodiment, the material is a silicone elastomer that comprises dimethyland methylvinyl siloxane copolymers and reinforcing silica. Uponinsertion, the adhesive, hydro gel, or other similar material can act toseal the cannula with the skin to form the necessary seal.

This advantage can be important for applications in which the length ofthe cannula is limited, such as for individuals having littlesubcutaneous tissue, such as a pediatric patient. The need for aneffective seal between a cannula and the skin increases as the length ofthe cannula decreases. The tapered wall portion 550 allows for the useof a shorter cannula while still providing effective sealing between thecannula and the skin.

Infusion devices made in accordance with the principles described hereincan be advantageous for various reasons. For example, the set can becoupled in various selectable rotational orientations with respect tothe site. In some embodiments, a plurality of orientations can beprovided. This allows a patient to rotationally orient the set (andassociated tube coupled to the set) as desired so that the tube canextend, for example, towards an infusion pump regardless of where thesite is placed on the body of the patient.

In addition, the set and associated tube can be removed from the sitemultiple times while leaving the site on the skin. This can be desirableif the patient wants to reorient the set with respect to the site, or ifthe patient wants to remove the set from the site for a period of time,such as if the patient wishes to shower and then replace the set ontothe site.

The engagement of the set with the site and sliding action of the setfrom the unlocked to locked position can also be advantageous in that apatient can preferably accomplish orientation and coupling of the set tothe site using a single hand. This can be preferable, for example, ifthe site has been placed on a portion of the body of the patient that isnot easily reached using two hands, or cannot easily be seen by thepatient (e.g., if the site is placed on the back of the patient).

Further, the configuration of the set functions to protect the patientfrom inadvertent contact with the hollow needle (e.g., needles 214 and411) used to pierce the diaphragm and deliver the substance to the site.For example, the outer arms 220 and 222 and the inner arms 226 and 228of the first member 210 of the set 200 generally surround the needle 214and function to reduce the chance that the patient will inadvertentlycontact the needle.

Also, the configuration of the diaphragm in the site can be preferablein that a single diaphragm can function to both allow introduction ofthe cannula of the site into the body using one needle, as well ascoupling of the set with the site using a second needle. In addition,the diaphragm can preferably be held within the site through frictionalengagement between the diaphragm and the site without requiringadditional structure to retain the diaphragm in the site.

Although examples of infusion devices have been described herein,various modifications can be made to the devices. For example, as notedabove the member 120 of the site 100 and the aperture 270 of the set 200can be formed in a variety of shapes to allow the set 200 to be orientedin multiple positions with respect to the site 100. In addition, aretaining member can be fitted over the open top of the member 120 tofurther retain the diaphragm 150 in position in the cavity 121. In yetother embodiments, site 100, including cannula 230 or 530, can beconfigured as an angled site, rather than a ninety-degree or rightangled site. In these embodiments, the site is introduced into the skinat an angle other than ninety-degrees, rather than being introduced at agenerally right angle.

In another alternative embodiment, the second member 250 of the set 200can be constructed to include a cover portion extending from the mainbody 260 so that when the set 200 is moved to the locked position thecover extends over the closed end 154 of the diaphragm 150 to reduceexposure of the set and site to outside contaminants.

The above specification, examples and data provide a completedescription of the manufacture and of the invention. Since manyembodiments of the invention can be made without departing from thespirit and scope of the invention, the invention resides in the claimshereinafter appended.

1. A site for a subcutaneous infusion device, the site comprising: abase positionable relative to skin of a patient; and a cannula extendingfrom the base and configured to be introduced into a subcutaneous layerof skin of the patient at a generally ninety-degree angle with respectto the skin using a needle; wherein the cannula includes first andsecond ends and defines a bore extending from the first end to thesecond end, the first end being coupled to the base; and wherein thecannula includes a tapered wall portion formed between the first andsecond ends and extending from adjacent to the base towards the secondend of the cannula, the tapered wall portion being tapered from agreater wall thickness to a lesser wall thickness as the tapered wallportion extends from the base towards the second end.
 2. The site ofclaim 1, wherein the tapered wall portion is positioned outside thebase.
 3. The site of claim 1, wherein a difference in diameter betweenthe greater wall thickness and the lesser wall thickness isapproximately 1 millimeter.
 4. The site of claim 1, wherein a length ofthe cannula from the tapered wall portion to the second end isapproximately less than 9 millimeters.
 5. The site of claim 4, whereinthe length of the cannula from the tapered wall portion to the secondend is approximately 6 millimeters.
 6. The site of claim 5, wherein thelength of the cannula from the tapered wall portion to the second end isapproximately 3 millimeters.
 7. The site of claim 1, wherein the firstend of the cannula includes a tapered top side opening into a reservoirdefined by the base.
 8. The site of claim 1, wherein the first end ofthe cannula includes a flanged portion having a bottom side configuredto engage a bottom surface in a cavity of the base, and a tapered topside opening into the cavity, and wherein the cannula extends through acentral aperture of the base generally perpendicular to the base suchthat the second end of the cannula is positioned outside the base. 9.The site of claim 1, further comprising: a single, unitary diaphragmcoupled to the base, the single diaphragm including a closed end, anopen end, and a sidewall, and the single diaphragm defining an internalreservoir in fluid communication with the cannula through the open end;wherein the single diaphragm is pierced by the needle through the upperend to introduce the cannula into the subcutaneous layer of skin of thepatient; and wherein the single diaphragm is pierceable through thesidewall to access the internal reservoir to deliver a substance to thepatient through the cannula.
 10. An infusion device, comprising: a siteincluding a base, a cannula extending from the base, and a seal in fluidcommunication with the cannula for delivering a substance through theseal and into the cannula, the cannula including a first portion that iscoupled to the base, a second portion extending from the first portion,and a third portion this is a free end, wherein the second portionincludes a wall portion that is tapered from a greater wall thickness toa lesser wall thickness as the wall portion extends from the firstportion to the third portion; and a set including a first memberincluding a needle, and a second member defining an aperture configuredto accept the site, wherein the first member is slideable relative tothe second member from an unlocked to a locked position, and wherein inthe locked position the needle extends into the aperture and through aportion of the seal of the site to deliver the substance to the site.11. The device of claim 10, wherein the first portion of the cannulaincludes a flanged portion having a bottom side configured to engage abottom surface in a cavity of the base, and a tapered top side openinginto the cavity, and wherein the cannula extends through a centralaperture of the base generally perpendicular to the base such that thesecond and third portions of the cannula are positioned outside thebase.
 12. The device of claim 10, further comprising: a single, unitarydiaphragm coupled to the base, the single diaphragm including a closedend, an open end, and a sidewall, and the single diaphragm defining aninternal reservoir in fluid communication with the cannula through theopen end; wherein the single diaphragm is pierced by the needle throughthe upper end to introduce the cannula into the subcutaneous layer ofskin of the patient; and wherein the single diaphragm is pierceablethrough the sidewall to access the internal reservoir to deliver asubstance to the patient through the cannula.
 13. The device of claim10, wherein the cannula is configured to be introduced into asubcutaneous layer of skin of the patient at a generally ninety-degreeangle with respect to the skin using a needle.
 14. A method of forming acannula for a site of an infusion device, the method comprising: forminga longitudinal body including first and second ends and defining a boreextending therethrough; defining a first portion at a first end of thebody configured to be coupled to a base of a site; defining a taperedwall portion of the body including a first wall thickness adjacent tothe first portion and a second wall thickness adjacent to a thirdportion of the body including a free end, the first wall thickness beinggreater than the second wall thickness, and the tapered wall portionbeing tapered as the tapered wall portion extends from the first wallthickness to the second wall thickness.
 15. The method of claim 14,further comprising positioning the tapered wall portion outside thebase.
 16. The method of claim 14, further comprising forming adifference in diameter between the first wall thickness and the secondwall thickness to be approximately 1 millimeter.
 17. The method of claim14, further comprising forming a length of the cannula from the taperedwall portion to the second end to be less than 9 millimeters.
 18. Themethod of claim 17, further comprising forming the length of the cannulafrom the tapered wall portion to the second end to be approximately 6millimeters.
 19. The method of claim 17, further comprising forming thelength of the cannula from the tapered wall portion to the second end tobe approximately 3 millimeters.
 20. The method of claim 14, furthercomprising forming a tapered top side opening in the first end of thecannula extending into a reservoir defined by the base.